What Is In Your Stove Right Now?

[Dieselhead]

@Dieselhead You got two BK40s now?? I do a top down every cold start. Wouldn’t do it any other way honestly

sig line says one King one Princess. Still, that's pretty awesome. One guy on this forum using more wood than me, other than those OWB nuts!

Correcto, 1+1. I guess doing a top down never appealed to me, because you know, fire burns upward. So if you start it at the top the kindling will burn out and the logs won’t catch. Maybe I just have to put physics aside as I see it does work in each one of your cold start pics with the pinecones 🤣

@Ashful i do not believe I will touch your wood or BTU consumption by far. These stoves loaf along (black box mode) where yours seem to full on inferno themselves through the season. That is my hope anyways 😎

 

[Ashful]

Correcto, 1+1. I guess doing a top down never appealed to me, because you know, fire burns upward. So if you start it at the top the kindling will burn out and the logs won’t catch. Maybe I just have to put physics aside as I see it does work in each one of your cold start pics with the pinecones 🤣

Top-down seems pointless to me, in a cat stove. We want to get the whole load engulfed as quickly as possible, not artifically control and extend the burn. Our stoves do that for us!

@Ashful i do not believe I will touch your wood or BTU consumption by far. These stoves loaf along (black box mode) where yours seem to full on inferno themselves through the season. That is my hope anyways 😎

Misery loves company. I was out splitting wood again today, as I was last weekend, the weekend before that, the weekend before that...

One of my stoves always runs black box mode, but the other is often throttled up higher, sometimes full loads WOT. But this time of year, it's just half loads for the overnight, usually run black.

 

[stoveliker]

I do top down because I think the cat gets warmer quicker that way. So I close the bypass sooner (and run high for a bit more after that to get the load going well before I dial down).

 

[MRD1985]

sig line says one King one Princess. Still, that's pretty awesome. One guy on this forum using more wood than me, other than those OWB nuts!

iPhone doesn’t show me signatures. Thanks

 

[Turbo89]

Summit has some oak, ash, and a few red maple / birch rounds.

The oak was a little damp from the rain, so she took a while to light off.

 

[Dieselhead]

I do top down because I think the cat gets warmer quicker that way. So I close the bypass sooner (and run high for a bit more after that to get the load going well before I dial down).

See, I load kindling right inside the door and the fire runs up the face of the logs dancing around the face of the cat, where if I do a top down the fire goes up the flue after bouncing off the bypass chamber a little bit, behind the cat. That’s why I always did a bottom up burn. I figured it gets the cat hotter, quicker.

Anyhow, basement at 70, started at 62, still a half load of wood left in the box, stat at 4:00 position overnight. STT of 325. This stove burns much different than my King’s thermostat setting wise. Flue is the biggest contributor to that is what I’m thinking.

 

[bigealta]

How/Why Top Down works:

A fire radiates thermal energy in a 360-degree pattern primarily through thermal radiation (electromagnetic infrared waves), which travels outward in all directions from the source.

Key Reasons Top-Down Fires Excel

• • Instant Flue Priming and Draft: Lighting the fire at the top puts the initial heat source right near the flue outlet or chimney neck. This warms the cold air inside the chimney liner immediately, establishing a strong upward vacuum (draft) before heavy smoke can build up. [1, 2, 3]
  • Cleaner Combustion and Less Smoke: In a conventional fire, cold logs smother the flame or release unburnt gases and hydrocarbons that escape as smoke and create creosote. In a top-down burn, any smoke or gases released from the lower wood must travel up through the hot flames at the top, which reburns and incinerates those particles cleanly. [1, 2, 3, 4, 5]
  • Gentle Preheating of Fuel: As the kindling and small pieces burn down, glowing embers drop naturally onto the larger logs beneath them. This gradually dries and preheats the heavy hardwood logs so they ignite smoothly without choking or smoking. [1]
  • Unobstructed Oxygen Flow: Stacking larger logs flat on the bottom with cross-hatched kindling on top creates a "pallet-like" structure with ample air gaps. Oxygen moves freely through the top layers without being choked by collapsing heavy logs. [1, 2]
  • Low Maintenance ("Set It and Forget It"): Because the fuel feeds downward on its own over several hours, you rarely need to poke, stir, or rush back to add wood during the critical startup phase.

 

[Ashful]

How/Why Top Down works:

A fire radiates thermal energy in a 360-degree pattern primarily through thermal radiation (electromagnetic infrared waves), which travels outward in all directions from the source.

Key Reasons Top-Down Fires Excel

• • Instant Flue Priming and Draft: Lighting the fire at the top puts the initial heat source right near the flue outlet or chimney neck. This warms the cold air inside the chimney liner immediately, establishing a strong upward vacuum (draft) before heavy smoke can build up. [1, 2, 3]
  • Cleaner Combustion and Less Smoke: In a conventional fire, cold logs smother the flame or release unburnt gases and hydrocarbons that escape as smoke and create creosote. In a top-down burn, any smoke or gases released from the lower wood must travel up through the hot flames at the top, which reburns and incinerates those particles cleanly. [1, 2, 3, 4, 5]
  • Gentle Preheating of Fuel: As the kindling and small pieces burn down, glowing embers drop naturally onto the larger logs beneath them. This gradually dries and preheats the heavy hardwood logs so they ignite smoothly without choking or smoking. [1]
  • Unobstructed Oxygen Flow: Stacking larger logs flat on the bottom with cross-hatched kindling on top creates a "pallet-like" structure with ample air gaps. Oxygen moves freely through the top layers without being choked by collapsing heavy logs. [1, 2]
  • Low Maintenance ("Set It and Forget It"): Because the fuel feeds downward on its own over several hours, you rarely need to poke, stir, or rush back to add wood during the critical startup phase.

Agreed on most of these points, except #3. But I'd still argue these advantages aren't as applicable to most cat stove installations:

1. Flue priming: Excepting the very rare scenario of wanting to light a fire when it's warm outside, my flue already works fine before I light any fire, no need to "prime" it. That said, I'm aware there are badly-designed setups that downdraft and require priming, so this may be an advantage for a select few operators.

2. Cleaner combustion and less smoke is achieved when you close the bypass damper. You will always get there quicker lighting bottom-up than top down, since you really can't close bypass until entire wood load is engulfed and charred.

3. Gentle preheating: What?!? Who cares about being "gentle" with the thing you're about to turn to ash. Stupid.

4. Unobstructed oxygen flow: This is the one that comes closest to being a legit advantage in a cat stove. Still loses out to issue 2, tho.

5. Set it and forget it: Sounds like a problem for non-cat burners, from everything I read here. It's certainly no issue for anyone running a BK stove, ours are already built to "set and forget".